This thread has some great info, sorry i missed it earlier on. I personally keep two different "variants" or "strains" . I keep 6 stripe burundi (I will continue to call them "frontosa" until the discussion is completed LOL) and also a Tanzanian Variant known as Mpimbwe or Mpimbwe blue. I have noticed and heard some things about these two types of fronts that i can share. These are mostly things i have seen in my own fish and are my own thoughts on it :
1. The mpimbwe (as are the zaire and zambians) are a much more intense or brighter blue than the burundi.
2. The mpimbwe have a thin lone ranger type mask around the eye area instead of a long vertical stripe that goes up and down over the eye like a burundi. The zaire have a similar mask but slightly wider.
3. All tanz, zambian, and zaires have a mask instead of a eye stripe.
4. The mpimbwe seem to have much more personality and interaction with me than my burundi. If i put my hand in the tank they will come over and eat right out of my hand, the burundi on the other hand hang back and just watch...
5. Zambian and Tanzanian look so similar it is extremely hard to tell the difference.
6. Zaire are also so similar it is often almost impossiable for the regular guy to tell what type he has purchased just by looking. Even experts can often only make a guess. You will see them often ask the person "what did the seller say they were ? " That is because they often cannot tell. It is the same for most of the Tanz. variants as well.
7. There is often a different look or shape to the masks and quality of blue color that will tell tanz from zaire though.
8. Burundi is the most common frontosa found in popular LFS. Burundi is the type that has been around the longest .
9. All Burundi get humps on the head, even females. Alpha males often get truly "massive" humps when kept in same conditions as tankmates.
10. All Gibberosa also get humps on the head but they are often much smaller and more refined looking.
11. It is very hard to tell juvie fronts apart until they start to mature and develop masks and color intensifies. One thing i noticed is that my Tanzanian juvies do not often (if ever) display what is known as "the stress bar" (a dark horizontal line going down the sides of the body in the light stripes that comes and goes with mood). My burundi juvies all displayed this and it would photograph easily. The mpimbwe almost never had that. One other thing i noticed is the blue on the mpimbwe fry at one inch or larger was more evenly distributed over head and dorsal than the burundi and was a different shade of blue, burundi was more ice blue/white and mpimbwe more robin egg blue or sky blue. The burundi blue also seems to be most concentrated on the lower parts of the body getting lighter as it goes up. Mpimbwe seem to have even bright blue all over.
12. I have noticed that it is often the case when someone is not sure of type of front they bring out words like " poor quality or hybrid". I have also found if you buy your fish at a LFS that marked them as "frontosa" and did not specify a location or collection point that even if they are pure burundi or other variant you will most often be told that they "must be low quality or hybrid" simply because of the belief that these stores do not order good stock. I find this to be true at most frontosa specialty sites. While in general you should get better stock from a breeder i have not always found that to be true. I personally have seen nice fish come from Lfs just as often as from a breeder. Its simply that most LFS dont specialize in fronts and dont know the difference, that does not mean the breeder or supplier of those fish didnt know either. That said i have also seen horriable stock from breeders. Use common sense when buying from a LFS, do your research first. I would recommend that you attempt to get good stock from a reputable breeder but if you cant find one in your area and the fish look healthy with nice stripes and good form and color at your local LFS then get them and dont worry about what other "experts" say. My burundi are from Petco and look like burundi and act like burundi. I am perfectly happy with them. I had one expert tell me once i should flush them and buy some "pure" fronts from him instead. Unless its some genetic faults such as lip deformity, broken stripes, 6 stripes on one side and 7 on other etc... avoid those.
Here are some pics :
Here is one of my 2 inch mpimbwe juvies (notice how the intense blue is not just on the lower fins but also the whole body and head area and dorsal fin ?)
Here is one of my 4-5 inch burundi (notice the fins are nice and blue but the body stripes are much lighter blue almost a ice white ):
The two larger fish in front are burundi (notice the stress bar i mentioned earlier on them?) notice the smaller mpimbwe behind them do not display that mark .